U.S. patent number 8,197,687 [Application Number 12/539,734] was granted by the patent office on 2012-06-12 for contaminant adsorbent fluted filter element.
This patent grant is currently assigned to Perry Equipment Corporation. Invention is credited to Daniel M. Cloud, John A. Krogue.
United States Patent |
8,197,687 |
Krogue , et al. |
June 12, 2012 |
**Please see images for:
( Certificate of Correction ) ** |
Contaminant adsorbent fluted filter element
Abstract
A contaminant adsorption filter element is provided that
includes a self-assembled monolayers on mesoporous supports (SAMMS)
contained in a filter element having a plurality of pockets such as
a fluted filter media. The plurality of pockets are filled with
mesoporous material that is functionalized for a target
contaminant. A method of making a filter element having mesoporous
material filled flutes is also provided.
Inventors: |
Krogue; John A. (Mineral Wells,
TX), Cloud; Daniel M. (Weatherford, TX) |
Assignee: |
Perry Equipment Corporation
(Mineral Wells, TX)
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Family
ID: |
41695370 |
Appl.
No.: |
12/539,734 |
Filed: |
August 12, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100044297 A1 |
Feb 25, 2010 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61090093 |
Aug 19, 2008 |
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Current U.S.
Class: |
210/282;
210/502.1; 210/284; 210/497.1; 210/457; 210/291; 210/492;
210/493.2; 210/493.4 |
Current CPC
Class: |
C02F
1/281 (20130101); B32B 3/28 (20130101); B32B
5/18 (20130101); B32B 7/12 (20130101); B82Y
30/00 (20130101); B01D 53/0431 (20130101); B32B
27/06 (20130101); B29C 53/562 (20130101); B32B
5/16 (20130101); B01D 2257/60 (20130101); B01D
2257/602 (20130101); B01D 2253/308 (20130101); B32B
37/20 (20130101); B32B 2264/108 (20130101); B29L
2031/14 (20130101); B32B 2307/718 (20130101); C02F
2305/08 (20130101); B01D 2259/4146 (20130101); B29L
2009/00 (20130101); B32B 2266/0278 (20130101); B32B
37/1292 (20130101); C02F 2101/20 (20130101) |
Current International
Class: |
B01D
27/02 (20060101); B01D 27/06 (20060101) |
Field of
Search: |
;210/282-284,288,289,291,317,484,487,492,493.1,493.2,493.4,493.5,494.1,497.1,502.1,457
;55/498,512,517 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
US. Appl. No. 12/468,386, filed May 19, 2009, Krogue et al. cited
by other .
I. Yuranov et al.; Structured Combustion Catalysts Based on
Sintered Metal Fibre Filters; Institute of Chemical Engineering
publication; Jul. 10, 2003; 12 pages, pp. 217-227; vol. 43 No. 3
ISSN: 0926-3373; Applied Catalysis B: Environmental; Elsevier
Science B.V. cited by other .
I. Yuranov et al.; Pd/Si0.sub.2 Catalysts: Synthesis of Pd
Nanoparticles with the Controlled Size in Mesoporous Silicas;
Journal of Molecular Catalysis A: Chemical publication; Feb. 3,
2003; 14 pages, pp. 239-251; vol. 192 No. 1-2 ISSN: 1381-1169;
Elsevier Science B.V. cited by other .
C. Horny et al.; Micro-Structured String-Reactor for Autothermal
Production of Hydrogen; Chemical Engineering Journal 101; 2004; 7
pages, pp. 3-9; Elsevier. cited by other .
L. Kiwi-Minsker et al.; Microstructured Reactors for Catalytic
Reactions; Institute of Chemical Engineering publication; Dec. 15,
2005; 20 pages, pp. 2-14; vol. 110 No. 1-2 ISSN: 0920-5861;
Elsevier B.V. cited by other .
I. Yuranov et al.; Metal Grids with High-Porous Surface as
Structured Catalysts: Preparation, Characterization and Activity in
Propane Total Oxidation; Institute of Chemical Engineering
publication; Mar. 8, 2002; 9 pages, pp. 183-191; vol. 36 No. 3
ISSN: 0926-3373; Applied Catalysis B: Environmental; Elsevier
Science B.V. cited by other .
B. Louis et al.; Synthesis and Characterization of MCM-41 Coatings
on Stainless Steel Grids; Catalysis Communications 3 publication;
2002; 5 pages, pp. 159-163; Elsevier Science B.V. cited by other
.
Koch-Glitsch; Gauze Structured Packing; Bulletin KGP-6; 2000; 8
pages, pp. 1-8; Koch-Glitsch, Inc. cited by other .
Samms Adsorbents by Steward; http://sammsadsorbents.com Website,
last visited Mar. 14, 2008; 27 pages. cited by other .
Southwest Screens & Filters;
http://southwest.e-start.be/eng/products-filtermedia.asp Website,
last visited Apr. 2, 2008; 2 pages. cited by other .
Koch-Glitsch; http://koch-glitsch.com Website, last visited Apr. 2,
2008; 6 pages. cited by other .
Montz Dividing Wall Columns; http://www.montz.de Website, last
visited Mar. 13, 2008; 8 pages. cited by other .
Bekaert; Metal filter elements and systems; product pamphlet; 2006,
15 pages, pp. 1-15; Bekaert Advanced Filtration SA. cited by
other.
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Primary Examiner: Savage; Matthew
Attorney, Agent or Firm: Reinhart Boerner Van Deuren
P.C.
Parent Case Text
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This patent application claims the benefit of U.S. Provisional
Patent Application No. 60/090,093, filed Aug. 19, 2008, the entire
teachings and disclosure of which are incorporated herein by
reference thereto.
Claims
What is claimed is:
1. A filter element, comprising: a filter media having a plurality
of pockets formed therein about a central axis; a pair of end caps
affixed to opposing axial ends of the filter media a contaminant
adsorbent material trapped in the plurality of pockets; and
circumferential partitions separating the pockets radially, wherein
the pockets are layered radially about the central axis, wherein
the pockets are separated by axially extending partitions, wherein
the pockets are angularly spaced about the central axis, and
wherein a radial flow path travels through the layered pockets.
2. The filter element of claim 1, wherein the filter media is a
fluted filter media comprising a face sheet; and a convoluted sheet
of material defining flutes extending generally between opposed
axial ends, the convoluted sheet being attached to the face sheet
and wound in a coiled configuration about the central axis to
define a plurality of flutes to provide the plurality of
pockets.
3. The filter element of claim 2, wherein the flutes are closed
proximate at least one axial end of the filter media by a sealing
composition applied between the convoluted sheet and the face
sheet, wherein the sealing composition forms a plurality of plugs
closing each of the plurality of the flutes; the plurality of plugs
providing at least in part or in whole the pair of end caps.
4. The filter element of claim 2, wherein the flutes are closed
proximate both opposed axial ends of the filter media, wherein the
filter element is a radial flow filter element, further including a
central chamber, at least one of the end caps defining a fluid port
communicating with the central chamber.
5. The filter element of claim 4, further comprising a perforated
support core situated in the central chamber around which the face
sheet and the convoluted sheet are coiled, the support core
defining a flow channel in communication with the fluid port.
6. The filter element of claim 2, wherein the contaminant adsorbent
material comprises self-assembled monolayers on mesoporous supports
(SAMMS).
7. The filter element of claim 6, wherein the SAMMS includes a form
of SAMMS particulate powder material trapped in the pockets, the
particulate powder material having an average particle size of
between 10 microns and 100 microns, wherein at least one of the
face sheet and the convoluted sheet has filtration efficiency of
greater than 99% for the average particle size of the SAMMS
particulate powder, and wherein at least 90% of the SAMMS
particulate powder material by weight falls into a size category
distribution of between 20 and 80 microns.
8. The filter element of claim 2, wherein each of the face sheet
and the convoluted sheet comprises the following characteristics:
(a) a Frazier Permeability of between about 6 and about 20 CFM @
5'' WG; (b) an average fiber diameter of between about 2 and about
50 microns; (c) a base weight of between about 30 and about 200
lb/3000 ft2; (d) an average pore size generally between about 2 and
about 80 microns; and (e) a Mullen burst strength of between about
5 and about 100 psi.
9. The filter element of claim 1, wherein the end caps close
opposed axial ends of the filter media, the filter media defining a
central cavity, one of the end caps having a fluid port
communicating with the central cavity, wherein the filter media
defines a radial fluid flow path between the central cavity and an
outer periphery of the filter media, and the radial fluid flow path
traveling through the plurality of pockets filled with the
contaminant adsorbent material.
10. The filter element of claim 1, wherein the contaminant
adsorbent material comprises a form of SAMMS particulate powder
material, the particulate powder material having an average
particle size of between 10 microns and 100 microns, wherein the
filter media which forms the plurality of pockets has filtration
efficiency of greater than 90% for the average particle size of the
SAMMS particulate powder, wherein at least 90% of the SAMMS
particulate powder material by weight falls into a size category
distribution of between 20 and 100 microns.
11. The filter element of claim 10, wherein the ratio of a length
to perimeter of the filter element is between 0.3 and 6.
12. The filter element of claim 1, wherein the contaminant
adsorbent material is adapted to remove heavy metals from a fluid,
including the removal by adsorption of at least one of mercury,
silver, lead, uranium, plutonium, neptunium, americium, arsenic,
cadmium, or a combination thereof.
13. The filter element of claim 1, wherein the contaminant
adsorbent material includes a porous particle made from
self-assembled monolayers on mesoporous supports (SAMMS), wherein
the porous particle has a pore size ranging from about 2 to 7
nanometers.
14. The filter element of claim 1, wherein the contaminant
adsorbent material includes porous particles comprising silica.
15. The filter element of claim 1, wherein the contaminant
adsorbent material includes carbon particles ranging from 8 to 30
mesh size.
16. The filter element of claim 1, wherein contaminants being
removed by the contaminant adsorbent material are different than
those removed by the filter media.
17. A fluted filter element, comprising: a fluted filter media
having opposed axial ends and a central cavity along an axis, the
fluted filter media comprising a face sheet and a convoluted sheet
attached to the face sheet and wound in a coiled configuration
about the axis to define a plurality of flutes, each of the flutes
being closed proximate to both opposed axial ends, wherein the
fluted filter media defines a radial fluid flow path between an
outer periphery of the fluted filter media and the central cavity,
wherein the radial flow path travels through a plurality of layers
of the face sheet and a plurality of layers of the convoluted
sheet, wherein a contaminant adsorbent material is filled in the
plurality of flutes.
18. The fluted filter element of claim 17, wherein the radial flow
path travels through between 3 and 30 layers of the face sheet and
the convoluted sheet combined.
19. The fluted filter element of claim 17, further comprising a
pair of end caps sealingly bonded to the opposing axial ends of the
filter media, at least one of the end caps including a fluid port
in communication with the central cavity.
20. The fluted filter element of claim 17, wherein the contaminant
adsorbent material includes a porous particle made from
self-assembled monolayers on mesoporous supports (SAMMS), and
wherein the porous particles have a pore size ranging from about 2
to 7 nanometers, and an average particle size of between 10 microns
and 100 microns, and wherein at least one of the face sheet and the
convoluted sheet has a filtration efficiency of greater than 90%
for the average particle size of the porous particles, and wherein
at least 90% of the SAMMS porous particles by weight falls into a
size category distribution of between 20 and 100 microns.
Description
FIELD OF THE INVENTION
This invention generally relates to filtration media, filter
elements, filtration systems and methods for the treatment of
contaminated fluids and more particularly to such apparatuses and
methods for the removal of toxic heavy metals utilizing a
contaminant adsorbent, an exemplary example being self-assembled
monolayers on mesoporous supports (SAMMS), that is contained in a
filter element, and/or to fluted filter elements.
BACKGROUND OF THE INVENTION
There are many situations where toxic heavy metals such as mercury
are contained in fluid streams (both gaseous and liquid). For
example, produced water from offshore oil platforms can have
mercury levels that range from less than 100 parts per billion
(ppb) in the gulf of Mexico to about 2,000 ppb in the Gulf of
Thailand. Complicating matters is that in many applications,
sediments and other undesirable particles may also be present in
many environmental applications. Removal of such toxic heavy metals
to acceptable levels, while the subject of a long felt desire and
need, has been typically satisfied with either inadequate,
difficult and/or expensive solutions.
The use of particles of self-assembled monolayers on mesoporous
supports (SAMMS) have shown to have substantial capabilities for
adsorbing toxic metal contaminants. An example SAMMS material is
disclosed in U.S. Pat. Nos. 6,326,326; 6,531,224; 6,733,835;
6,753,038; and 6,846,554, the entire disclosures of which are
hereby incorporated by reference. One type of SAMMS is thiol-SAMMS,
in which the mesoporous material is functionalized with molecules
of a thiol group. Thiol-SAMMS is commercially available as
particles in a powder-like form from Steward Environmental
Solutions, LLC of Chattanooga, Tenn. The SAMMS powder material
typically can have different particle diameters that are typically
in the range of between about 30 and about 200 microns (Steward
Environmental Solutions, LLC advertises an average diameter of 40
microns). On the one hand, providing a larger diameter is
beneficial from a fluid flow standpoint in that a fixed bed of
powder material allows for greater fluid flow. However, larger
adsorbent particles do not have as much effective available surface
area for contaminant adsorption. While smaller SAMMS powder
material provides for greater effective surface area and adsorption
potential, packing such small powder is highly restrictive to fluid
flow and can create difficulties from a fluid flow standpoint.
SAMMS has extremely fast kinetics and a sizeable loading capacity
(e.g. 0.4-0.6 grams HG/gram of THIOL-Samms adsorbent for terminal
HG concentration of 100-200 ppm). Additionally, SAMMS works through
covalently bonding for reliable retention of toxic metal
contaminant. SAMMS typically has a bulk density of between
approximately 0.2 g/cc and 0.4 g/cc.
Various examples have been disclosed for using such SAMMS powder
particles. For example, various SAMMS filtration systems are
disclosed in U.S. Patent Publication Nos. US 2007/0295204 A1
entitled "Systems And Methods For Flow-Through Treatment Of
Contaminated Fluid"; US 2007/0262027 A1 entitled "Layered Filter
For Treatment Of Contaminated Fluids"; US 2007/0262025 A1 entitled
"Canister For Treatment Of Contaminated Fluids"; US 2007/0256981 A1
entitled "Composite Adsorbent Block For The Treatment of
Contaminated Fluids"; and US 2007/0256980 entitled "Countercurrent
Systems And Methods For Treatment Of Contaminated Fluids". All of
these patent publications are incorporated by reference in their
entireties.
Filters of the type used for filtering particulate matter from
fluid sometimes include one or more layers of a porous filter
material that is formed into a convoluted pattern, often referred
to in the industry as fluted filter media. Fluted filter media is
commonly used in construction of filter elements. Fluted filter
media is typically formed by winding a convoluted sheet and a face
sheet about an axis to form a plurality of contiguous adjacent
flutes. In one common form of such fluted filter media, alternating
ends of adjacent flutes are blocked to cause fluid entering one
open end of "inlet" flutes to flow through the porous filter media
into adjacent "outlet" flutes prior to exiting the filter media at
an opposite end of the flutes. As the fluid flow through the wall
of porous material from the first flutes to the adjacent flutes,
particulate matter in the fluid is filtered out of the fluid and
trapped in the first flutes and the porous filter material of the
wall. Prior such filter elements are disclosed in U.S. Pat. No.
7,329,326 (Wagner, et al.) and U.S. Patent Application Publication
No. 2006/0091084 (Merrit et al.), herein incorporated by reference
in their entireties.
The present invention pertains to improvements to the state of the
art.
BRIEF SUMMARY OF THE INVENTION
In one aspect, the invention provides a filter element comprising a
filter media having a plurality of pockets formed therein about a
central axis, a pair of end caps affixed to opposing axial ends of
the filter media, and contaminant adsorbent material trapped in the
plurality of pockets.
In accordance with the aspect above, one embodiment uses fluted
filter media to provide pockets. In such an embodiment, the
contaminant adsorbent material may comprise self-assembled
monolayers on mesoporous supports (SAMMS). The SAMMS material can
be filled in a plurality flutes of the fluted filter media, wherein
the SAMMS material is designed to remove heavy metals from a
fluid.
In another aspect, the invention provides a fluted filter element
comprising a fluted filter media having opposed axial ends and a
central cavity along an axis. The fluted filter media comprises a
face sheet and a convoluted sheet, wherein the convoluted sheet is
attached to the face sheet and wound in a coiled configuration
about the axis to define a plurality of flutes. Each of the flutes
is closed proximate both opposed axial ends, wherein the fluted
filter media defines radial fluid flow path between an outer
periphery of the fluted filter media and the central cavity (e.g.
either radially inward or outward flow, or both).
In yet another aspect, the invention provides a method of making a
filter element comprising steps of forming a filter media having a
plurality of pockets about a central axis, filling the plurality of
pockets with a contaminant adsorbent material, and sealing opposing
axial ends of the filter media.
Other aspects, objectives and advantages of the invention will
become more apparent from the following detailed description when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings incorporated in and forming a part of the
specification illustrate several aspects of the present invention
and, together with the description, serve to explain the principles
of the invention. In the drawings:
FIG. 1 is a partial cut-away and partially schematic perspective
illustration of a filtration vessel having a plurality of
cylindrical contaminant adsorbent filter element therein;
FIG. 2 is a schematic cross sectional view of a contaminant
adsorbent filter element wherein end caps are sealed by a plastic
welding method according to an embodiment of the present
invention;
FIG. 3 is a schematic cross sectional view of a contaminant
adsorbent filter element wherein end caps are sealed using a
sealing material filled in the end caps according to a different
embodiment of the present invention;
FIG. 4 is a schematic cross sectional view of a contaminant
adsorbent filter element wherein end caps are formed by plugs
according to yet another embodiment of the present invention;
FIG. 5 is a schematic illustration depicting a method of making a
fluted filter media wherein one end of the fluted filter media is
sealed with adhesive according to one embodiment;
FIG. 6 is a schematic illustration depicting a method of making a
fluted filter media wherein both ends of the fluted filter media
are left open according to a different embodiment;
FIG. 7 is a perspective view of a fluted filter media, ready to be
filled with SAMMS powder particles according to on embodiment;
FIG. 8 is a schematic illustration depicting a method of making a
fluted filter media, wherein SAMMS powder particle is filled during
the process of making the fluted filter media, wherein both ends of
the fluted filter media are sealed with adhesive according to one
embodiment; and
FIG. 9 is a schematic illustration of a helical winding methodology
for winding a contaminant adsorbent filter element according to one
embodiment.
While the invention will be described in connection with certain
preferred embodiments, there is no intent to limit it to those
embodiments. On the contrary, the intent is to cover all
alternatives, modifications and equivalents as included within the
spirit and scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION OF THE INVENTION
According to embodiments of the present invention, a filter element
includes a plurality of pockets formed of a filter media wherein
contaminant adsorbent material is enclosed for treatment of
contaminated fluids. An exemplary contaminant adsorbent material
used according to embodiments is preferably a nanoadsorbent
material manufactured from self-assembled monolayers on mesoporous
supports (SAMMS). An exemplary filter media to provide the pockets
is fluted filter media. However, it will be appreciated that
broader aspects of the present invention may be applicable to other
containment adsorbents and filter medias.
FIG. 1 shows one embodiment of the present invention in the form of
a filter element 10, adapted for insertion into a filtration vessel
34 through which contaminated fluid may be directed for subsequent
removal of contaminants within the fluid therefrom. In the vessel
34, the filter elements 10 are immersed in a flow of contaminated
fluid to permit removal of contaminants by contaminant adsorbent
material trapped in the filter media pocket of the filter elements
10.
Fluids which may be treated in connection with the present
invention maybe viscous, such as oil, or non-viscous, such as a
liquid or gas. Contaminants that may be removed by the filter
element 10 includes, but not limited to, heavy metals such as
mercury, cadmium, arsenic, and lead from complex fluids or
contaminated streams, such as produced water, and mercury from
variety of contaminated solutions and contaminated oils. The term
fluid as used herein is intended to include either liquid or
gas.
The filter element 10 shown in FIG. 1 is generally cylindrical
shape comprising a fluted filter media 16, and end caps 20, 22.
Preferably, the filter element 10 is constructed to be relatively
long and narrow, i.e. a large length to perimeter ratio. Typically,
the filter element 10 is constructed to have a length to perimeter
between 0.3 to 6, preferably between 1 to 3. For example, filters
may have an axial length of between 5 and 88 inches, and a
substantially circular cross section with a diameter of between 3
and 6 inches; and a perimeter of between 9 and 18 inches. In other
embodiments, the filter element 10 may be configured to have
various shapes such as race track, oval, or rectangular cross
sections.
A schematic cross sectional illustration of the filter element 10
is shown in FIG. 2, which provides a general overview of the filter
element 10 having a plurality of pockets 12 filled with contaminant
adsorbent material. In this embodiment, the plurality of pockets 12
is provided by the plurality of flutes 13. As shown, the fluted
filter media 16 having a plurality of flutes 13 is formed around a
perforated core 24 extending about a central axis 18. The plurality
of flutes 13 is filled with a SAMMS material 14 and attached to the
pair of end caps 20, 22 at opposed axial ends.
One of the end caps is an open end cap 20 having an opening in the
center defining a fluid port 28 which provides communication with a
central chamber 26. The open end cap 20 may be sealingly bonded to
one end of the fluid filter media 16. The other end of the filter
media 16 may be sealingly bonded to a closed end cap 22. By
sealingly bonded, it is meant that it is integrally bonded such as
by plastic welding as may be the case with plastic end caps or may
be potted with plastisol or other adhesive material or otherwise
attached with a sealing relationship to enclose the SAMMS material
14 within the flutes 13.
Conventionally, fluted filter elements are configured to have an
axial fluid flow path as described in U.S. Patent Publication No.
2006/0091084, entitled "Fluted Filter Media with Intermediate Flow
Restriction and Method of Making Same," assigned to the Assignee of
the present invention and incorporated herein by reference. In such
fluted filter elements, a fluid flows axially from one flow face,
through the fluted filter media longitudinally, to the opposing
flow face.
In contrast, the filter element 10 of the present invention can be
configured as a radial flow filter element. In filter element 10,
the fluid port 28 may either be an inlet port or an outlet port
depending upon the flow configuration. That is, a fluid may flow
radially inward from the outer periphery 32 of the fluted filter
media 16, through the plurality of flutes 13 filled with the SAMMS
14 and into the central chamber 26, wherein it may flow axially
toward the fluid port 28, then exit through the fluid port 28, as
shown by a fluid path 30. Alternatively, the fluid port 28 may be
an inlet port in which an unfiltered fluid enters the fluid port
28, and flows axially through the central chamber 26, then flows
radially through the plurality of the flutes 13 filled with the
SAMMS 14 toward the outer periphery 32, and exit through the outer
periphery 32 of the fluted filter media 16. In one embodiment a
fluid may travel through between 3 and 30 layers of the face sheets
42 and the convoluted sheets 40. As the fluid flows through the
filter element 10, solids and contaminants in the fluid may be
filtered by the convoluted sheets 40 and the face sheets 42, and
adsorbed by the SAMMS material 14. Alternatively, the convoluted
sheet 40 and the face sheet 42 may merely hold and fix the SAMMS
material 14 within the filter element 10 without performing a
filtration function. For example, the filter element 10 may be used
in a multi-stage filtration/contamination removal system, wherein a
separate filter element including a superior solid filtration
capability than the convoluted sheet 40 and the face sheet 42 is
provided in the upstream of the filter element 10. As such,
substantially all solids may be filtered by the upstream filter
element, and thus, the convoluted sheet 40 and the face sheet 42
may not perform filtration function.
FIG. 5 illustrates a construction of the fluted filter media 16.
The fluted filter media 16 may be formed from a convoluted sheet 40
secured together with a face sheet 42. Each of the convoluted sheet
40 and the face sheet 42 are made of a porous filter media. The
convoluted sheet 40 and the face sheet 42 may be formed from a same
filter media or different filter medias. For example, the
convoluted sheet 40 may be formed of a filter media that is less
open than a filter media used to form the face sheet 42. One
embodiment, each of the convoluted sheet 40 and the face sheet 42
are constructed from a same porous filter media having
characteristics of: (a) a Frazier Permeability between about 6 and
about 20 CFM @ 5'' WG, an average fiber diameter of between about 2
and about 50 microns, a base weight of between about 30 and about
200 lb/3000 ft.sup.2, an average pore size generally between about
2 and about 80 microns, and a Mullen burst strength between about 5
and about 100 psi.
The convoluted sheet 40 may be formed by any appropriate process,
such as corrugating or pleating, but preferably by gathering as
described in U.S. patent application Ser. No. 10/979,390, entitled
"Gathered Filter Media for an Air Filter and Method of Making
Same," assigned to the Assignee of the present invention, and
incorporated herein by reference. As shown in FIG. 5, the
convoluted sheet of porous filter material 40 forms a plurality of
contiguous adjacent convolutions, commonly known in the industry as
flutes. That is, the convoluted sheet 40 forms peaks and valleys,
then the convoluted sheet 40 is attached to the face sheet 42, with
adjacent peaks being generally regularly spaced from one
another.
The face sheet 42 is attached to the convoluted sheet 40 and
retains the convoluted sheet 40 in a convoluted state. The face
sheet 42 may be attached to the convoluted sheet 40 in any
appropriate manner, such as by beads of adhesive 44 applied at
junctures of the convoluted sheet 40 and the face sheet 42. As
illustrated in FIG. 5, alternating layers of the face sheet 42 and
the convoluted sheet 40 are secured to one another with adhesive 44
disposed on the face sheets 42. An adequate amount of the adhesive
44 is applied to secure the convoluted sheet 40 to the face sheet
42 without blocking pockets formed in the flutes 13. The face sheet
42 is shown as a flat sheet of porous material, however, the face
sheet 42 may not be flat in other embodiments. For example, the
face sheet 42 may include convolutions or pleated in various
directions.
In conventional axial flow filter elements, selected ends of the
flutes may be blocked, with a bead of adhesive, for example, to
cause fluid entering one end of some of the flutes to flow through
the porous filter media into other flutes prior to exiting the
filter media at an opposite end of the flutes, in the manner known
in the art. However, as discussed above, the filter element 10
according to the present invention is a radial flow filter element
with the flow paths between the outer periphery 32 of the fluted
filter media 16 and the fluid port 28. The flutes 13 of this
embodiment are filled with the SAMMS 14 and sealed at both ends to
prevent a fluid from exiting out though open ends of flutes 13. The
sealed flutes also contain the SAMMS powder particles 14 within the
flutes 13.
Further, the filter element 10 comprising a radial flow fluted
filter media according to the present invention includes the
convoluted sheet 40 and the face sheet 42, both of which are formed
of a porous filter material to allow a fluid to flow radially
across multiple layers of convoluted sheet 40 and face sheet 42.
The flutes 13 formed by the convoluted sheet 40 are substantially
equal in size and equally spaced in this embodiment, but in other
embodiments of the invention, this need not necessarily be the
case.
The fluted filter media 16 is coiled around the core 24. The core
24 as shown in FIGS. 1-7 includes a cylindrical wall 58 and a
center cavity defining the central chamber 26. The wall 58 of the
core 24 is perforated to allow a fluid to flow through the
perforation into/from the center chamber 26. The core 24 may be
formed into various shapes from any suitable materials such as a
polymeric material. The shape of the core can determine a general
shape of the filter element 10, as the fluted filter media 16 is
wound on the core 24. For example, the cylindrical core 24 of this
embodiment can form the cylindrically shaped filter media pack 16
as shown in FIGS. 1 and 7. In other embodiments, the filter media
pack may be formed into other shapes having a non-circular cross
section such as a race-track shape or rectangular shape.
During a winding process, a leading edge of the fluted filter media
16 including the convoluted sheet 40 secured together with the face
sheet 42 may be taped to the surface of the core 24, then wound on
the central core 24. In some embodiments, an optional layer 25 of
porous filter media material may be provided between the core 42
and the fluted filter media 16. That is, the optional layer 25 is
wound on the core 24 first, then the fluted filter media 16 can be
wound on the top of the optional layer 25. In such embodiments, the
optional layer 25 may be constructed with a same filter media
material as the filter media material of one of the convoluted
sheet 40 and the face sheet 42, or may be formed of a different
filter media material. Preferably, the optional layer 25 is formed
of a filter media material having a better filtration efficiency
against the SAMMS powder particulates than the filter media
materials forming the convoluted sheet 40 and the face sheet 42,
such that any SAMMS powder particulates that move across the
convoluted sheet 40 and the face sheet 42 may be contained,
thereby, minimizing amount of SAMMS powder particulates in a
filtered fluid stream. As discussed above, an adequate amount of
adhesive 44 is applied on the face sheet 42 to secure together the
convoluted sheet 40 and the face sheet 42 as the face sheet 42 and
the convoluted sheet 40 are wound together on the core 24. In other
embodiments, the fluted filter media 16 may be formed without a
core 24.
The flutes 13 of the fluted filter media 16 shown in FIG. 5 are
sealed at one end with adhesive 44 applied on the convoluted sheet
40 approximate one edge by an adhesive applicator 52. Since the
purpose of applying adhesive 44 using the applicator 52 is to seal
the end of the flutes 13, the applicator 52 may apply more adhesive
than the other applicators 60, 62, such that the excess adhesive
can fill the flutes 13 formed as the face sheet 42 is attached to
the convoluted sheet 40 and wound on the core 24. As shown in FIG.
4, the adhesive 44 applied on the edge (see FIG. 5) forms plugs 33
which may define an end cap. In other embodiments, the closed end
cap 22 may additionally attached to the closed end of the fluted
filter media 16, such that the closed flute face of the filter
media 16 is secured to the closed end cap 22 as shown in FIG.
7.
Alternatively, as shown in FIG. 6, the flutes 13 of the fluted
filter media 16 may not be closed by adhesive 44. In such an
embodiment, both ends of the flutes 13 are left open. Once a web of
the fluted filter media pack 16 is formed on the core 24, the
closed end cap 22 may be sealingly attached to one of the fluted
filter media pack 16. Referring to FIG. 3, one way to sealingly
attaching the closed end cap 22 is by filling the closed end cap 22
with a plastisol material 36 and pressing the plastisol filled
closed end cap 22 to the one end of the fluted filter media pack 16
such that some of the plastisol material 36 enters openings formed
by the flutes 13, thereby sealing the interface between the close
end cap 22 and the fluted filter media pack 16. Alternatively,
other suitable sealing materials or adhesives may be used instead
of the plastisol. In other embodiments, the open end cap 20 may be
sealingly bonded to the fluted filter media pack 16 first.
Now referring to FIG. 2, another way of sealingly attaching an end
cap to the fluted filter media 16 is by a plastic welding process,
wherein a portion of the end cap adjacent to one end of the fluted
filter media 16 is formed of a suitable thermoplastic material,
wherein the thermoplastic material portion of the end cap is heated
to soft, and pressed against one end of filter media 16 such that
some of the softened thermoplastic material enters openings formed
by the flutes, thereby sealingly attaching the fluted filter media
16 and the end cap. The material of end caps in FIG. 2 (and other
embodiments) could alternatively be a molded in place material such
as foamed urethane.
Once the closed end cap 22 is attached to the one end of the fluted
filter media 16, the fluted filter media 16 is placed with the open
flute face up such that the SAMMS powder material can be filled and
packed into each of the flutes 13. Typically, the flutes 13 can be
packed with 0.2 to 0.50 g/cm.sup.3 SAMMS, preferably, 0.25 to 0.35
g/cm.sup.3.
After the flutes 13 are packed with the SAMMS powder material 14,
the open end cap 20 is sealingly attached to the open flute face
54. The open end cap 20 may be sealed to the open flute face 54 by
any adequate methods including methods described above with regard
to sealingly attaching the closed end cap 22 to one end of the
fluted filter media pack 16. For example, the open end cap 20 may
be first applied with a platisol material then pressed onto the
open flute face 54. Then, the filter element 10 may be flipped over
and further pressed to sealingly attach the open end cap 20.
In an alternative embodiment, the SAMMS powder material 14 may be
filled as the fluted filter media 16 is formed and wound on the
core 24. Such embodiment is shown in FIG. 8, wherein the SAMMS
powder material 14 is deposited on the convoluted sheet 40 via a
feeding device 64. The amount of the SAMMS powder material 14 fed
may be controlled to fill each of the flutes 13 without
overflowing. As shown, each end of the flutes 13 are closed with
the adhesive 44 applied via the adhesive applicators 84 and 86. The
resulting fluted filter media 16 will have the half of the flutes
13 filled with the SAMMS powder material 14. In other embodiments,
a second SAMMS feeding device may be installed in the front end to
fill the flutes 13 as the convoluted sheet 40 is laminated to the
face sheet 42. Thus, all of the flutes 13 in such embodiments are
filled with the SAMMS powder material 14. In this embodiment each
end of the fluted filter media 16 is sealed with plugs 33, as shown
in FIG. 2, formed by the adhesive 44, which can function as end
caps. In some embodiments, additional end caps 20, 22 may be
attached to the SAMMS filled fluted filter media 16.
The open end cap 20 may include an appropriate annular seal to
provide for sealing of the filter element when it is installed into
an appropriate filtration vessel 34. Additionally, a pre-filter
outer wrap or jacket may also be affixed around the outer periphery
32 of the filter element 10 such that prior to passing through the
SAMMS filled flutes 13, a contaminated fluid may first flow through
a particulate loading filtration media. It is also understood that
the invention is not limited to a filter media pack of fluted
media. Those having skill in the art will readily recognize that
the invention may also be practiced with efficacy, using other
types of filter media having a plurality of pockets. It will also
be recognized that each embodiment of FIGS. 2-4 and 7 each include
end caps at either end that may be a unitary one piece end cap as
shown in FIGS. 2 and 4 or an end cap assembly of different
materials as shown in FIG. 3.
In the embodiments according to the present invention, the SAMMS
powder material 14 is trapped in the plurality of flutes 13 such
that channeling and short-circuiting of fluid though an unsecured
packed SAMMS particle bed can be avoided. In such industrial
filtration applications, a sizeable flow rate can be experienced
which can channel and/or otherwise move SAMMS powder particles to
create uneven flow through a packed powder bed. For example, flux
rates based upon perimeter surface area in filtration applications
such as embodiments herein may be between about 0.1 cubic meters
per hour per square meter and 2.0 cubic meters per hour per square
meter for liquids and other fluids. By capturing the SAMMS powder
particles into the plurality of pockets, uniform loading of toxic
metals may be achieved throughout the structured bed, and fluid
flow does not cause displacement of the SAMMS powder material. That
is, the SAMMS powder material is generally fixed within each pocket
and maintained in communication with fluid flow supported by the
fluted filter media structure.
A mesoporous support of a nanosorbent material manufactured from
self-assembled monolayers on mesoporous supports (SAMMS), in an
embodiment, may be formed from various porous material, including
silica, alumina, zeolite or other suitable mesoporous material.
During a manufacturing process of a SAMMS, the mesoporous support
is deposited with self-assembled monolayer along its outer surface
which are functionalize to provide a desired contaminant adsorbent
property. For example, functionalizing the mesoporous material with
a thiol group provides for mercury adsorption property. Other
functional molecules may be used in the alternative and/or in
combination to provide for different contaminant adsorption
properties, which may include, but not limited to, thiol, amine,
thioalkoxide, polycarboxylic acids, ehtylenediamine, bipyridyl,
phenanthroline, phenols, polyhydroxyaromatic, carbonyl compounds,
phosphine, phosphine oxide, isonitrile and combinations thereof.
Target metals or metal compounds that may be bound include but not
limited to As, Bi, Cd, Co, Cu, Pb, Hg, Ni, Pt, Ru, Rh, Se, Ag and
combinations thereof.
An example of a SAMMS that can be used in connection with the
present invention is thiol-SAMMS, such as that disclosed in U.S.
Pat. No. 6,326,326, the entire disclosure of which is hereby
incorporated by reference. Other examples of the contaminant
adsorbent material which can used in the present invention
includes, but not limited to, commercially available carbon
particles having a particle size ranging from about 8 to about 30
mesh in size. Commercially available SAMMS powders are available
from Steward Environmental Solutions.
The SAMMS material 14 may include porous particles ranging from
about 1 micron to about 200 microns in size, preferably with an
average particle size between 10 microns-100 microns, more
preferably, with at least 90% of particles by weight between 20
microns-100 microns. In one embodiment, the SAMMS material 14 has a
mean particle size between 20 microns-100 microns, more preferably,
between 30 microns-80 microns. The contaminant adsorbent porous
particles may include a pore size ranging from about 2 nanometers
(nm) to about 7 nm and may be provided with an apparent density
ranging from about 0.2 grams/milliliter to about 0.4
grams/milliliter.
Considering the size of the contaminant adsorbent material particle
size, the filter media 16 having the plurality of pockets 12 is
formed from an appropriate filter media material having a porosity
to contain the contaminant adsorbent particles within each of the
plurality of pockets 12 and to minimize movement of the contaminant
adsorbent particles across each of the plurality of pockets 12. For
example, in an embodiment, at least one of the face sheet 42 and
the convoluted sheet 40 of the fluted filter media 16 has
filtration efficiency of greater than 99% for the average particle
size of the SAMMS particulate powder 14.
The mesoporous material such as SAMMS 14 is typically a form of a
molecular sieve that possesses ordered pores on a submicrons level
(e.g. pore sizes typically between 2 and 30 nanometers, and more
typically 3-4 nanometers in one embodiment), typically with a
narrow size distribution, and a high surface area (up to 1200
square meters/g) with an apparent density that may range from about
0.2 grams/milliliter to about 0.4 grams/milliliter. The mesoporous
material 14 substantially fills each of the plurality of flutes 13,
and as a fluid flows through the fluted filter media 16 filled with
the mesoporous material 14, the functional molecules carried on the
surface of the mesoporous material particles 14 are subjected to
and interact with the fluid and adsorb contaminant in a fluid
stream. However, the flow rate of fluid through a filter element is
not controlled by the characteristics of these mesopores. Rather,
the mesopores increase functional surface area and ability for
functional molecules to act as a contaminant adsorbent. Fluid flow
rate through filter element is substantially determined and thereby
controlled the density of the mesoporous material 14 trapped in the
plurality of flutes 13 (e.g. amount of the mesoporous material
packed in each of the flutes), and porosity of the fluted filter
media 16.
In one embodiment, a contaminated fluid may flow through the filter
element 10 in a radial fluid path as described previously, wherein
the contaminated fluid is permitted to flow through the pores of
the particles in the SAMMS powder material. Within these pores,
particular contaminants, such as heavy metals (e.g. mercury) come
in contact with a monolayer of chemical designed to attract and
bind the molecules of these contaminants. As such, these particular
contaminants may bond to the SAMMS and removed from the fluid. Once
the SAMMS material is used up or spent, the filter element 10 can
be changed to a new filter element in the vessel 34. To the extent
desired, the spent SAMMS may be regenerated. In particular, the
spent SAMMS may be treated with an acidic fluid to remove the
adsorbed contaminant.
To determine when the SAMMS material may be used up, several
approaches may be implemented. For example, as the filter element
10 is loaded with contaminants, its differential pressure may
increase. This is because contaminants in the fluid once trapped by
the SAMMS material will tend to plug the tightly packed SAMMS
material over time. As such, it will be important to monitor the
differential pressure of the filter media 10. Further, although the
primary purpose of the SAMMS material is to adsorb a particular
contaminant, due to its small particle size (i.e. from about 5
microns to about 200 microns), the SAMMS may also be a very good
solids filter. This ability to filter solids can result in the
SAMMS material be spent of plugged sooner than otherwise
necessary.
To that end, the convoluted sheet 40 and the face sheet 42 can
increase a life span of the SAMMS material, since solids can be
filtered by these sheets. Additional filter medias maybe provided
strategically in the vessel 34 to filter solids before the
contaminated fluid reach the filter element 10 to minimize plugging
by solids, for example, a pre-filter either in the same filter
element or more preferably in a separate upstream particulate
filtration element (either surface loading barrier filtration or
depth loading filtration or a combination thereof.) Preferably,
such a pre-filter should have an absolute efficiency rating (e.g.
greater than 90%) for the standard operating fluid flow rate of an
application of between about 1 microns and about 5 microns, and
more preferably at least a 3 microns efficiency pre-filter or
better.
In other approach, the status of the SAMMS may be determined by
periodically or continuously monitoring the level of contaminants
of the treated fluid in an outlet stream. When the level in the
outlet stream increases to a certain point, the filter element 10
may be changed or regenrated.
Turning to FIG. 9, another generally cylindrical filter element and
method for making the same is illustrated in which a fluted filter
media 70 and other suitable filter material may be wound into
helically configured filter element 80. This can be done according
to the principles of U.S. Pat. No. 5,893,956 entitle: "Method of
Making Filter Element"; and/or pending Patent Application
Publication No. 2008/0128364, entitled: "Filter Element and Method
of Manufacturing and Using Same" filed by Dan Cloud and John A.
Krogue with a filing date of Dec. 1, 2006; these patent documents
are assigned to the present assignee and the entire disclosures of
these two patent documents are hereby incorporated by reference in
their entireties.
In this embodiment, the fluted filter media 70 is constructed with
a convoluted sheet 76 attached to face sheets 72, 74 on each side
of the convoluted sheet 76. The filter media 70 is filled with the
SAMMS powder material 14 using methods similar to the method
described previously for the embodiment shown in FIG. 8.
As shown in FIG. 9, multi-overlapped filter element 80 is formed
from the SAMMS filled fluted filter media 70 and other suitable
filter media 78. The other suitable filter media 78 may be the
SAMMS filled fluted filter media 70, a depth loading or
surface/barrier loading filtration media, a porous spacer element
that provides little or no filtration, a SAMMS coated lattice
structure, or other suitable media. While only one of the strips
shown in FIG. 9 may be filled with SAMMS or coated with SAMMS, it
is understood that all of the strips may include SAMMS such as the
SAMMS filled fluted filter media or different types of SAMMS coated
wire mesh material as disclosed in U.S. Provisional Patent
Application No. 61/056,898, entitled "Contaminant Adsorption
Filtration Media, Elements, Systems and Methods Employing Wire or
Other Lattice Support" which is assigned to the present assignee
and the entire disclosure of which is hereby incorporated by
reference in their entirety.
As it was with the filter element 10, the helically wound filter
element 80 may include a perforated core 24 and end caps 20, 22
sealingly bonded to each end of the filter element 80. Again, one
end cap 20 is open, defining the fluid port 28 that communicates
with the central chamber 26, and may carry a seal to provide for
sealing with a housing vessel 34. The fluid flows generally
radially through the filter element 80 as previously described with
regard to the filter element 10.
The filter element 80 may be constructed only as a contaminant
adsorption media with filter media including SAMMS material such as
the SAMMS filled fluted filter media and SAMMS coated wire mesh
strips either with or without more porous spacer strips that really
do not serve a filtration function. Alternatively, the filter
element 80 may be configured as a combination waste adsorption and
particulate loading filtration element (with barrier filtration
and/or depth filtration loading). More conventional polymeric
filter media materials may be wound in combination with the SAMMS
filled fluted filter media and/or SAMMS coated wire mesh material.
Different configurations can be employed and the teachings of the
U.S. patent records noted above may be used to create different
configurations.
The filter element 10 as described above is filled with a
contaminant adsorbent material such as the SAMMS material 14 to
remove contaminants from a fluid. However, in other embodiments,
the filter element 10 may also be used without any contaminant
adsorbent material. For example, each of the flutes 13 of the
filter element 10 may be plugged using one of the methods discussed
previously, such that fluid cannot enter or exit from openings
formed by the flutes 13. As discussed above, such filter element
construction results in a fluted filter element having a radial
flow path. The flutes 13 in such embodiments can remain void,
wherein the convoluted sheet 40 and the face sheet 42 may perform
filtration of solids as the fluid travels between the outer
periphery 32 of the filter element and the core 24. In other
embodiments, the flutes 13 may be filled with other suitable solid
filtration materials.
All references, including publications, patent applications, and
patents cited herein are hereby incorporated by reference to the
same extent as if each reference were individually and specifically
indicated to be incorporated by reference and were set forth in its
entirety herein.
The use of the terms "a" and "an" and "the" and similar referents
in the context of describing the invention (especially in the
context of the following claims) is to be construed to cover both
the singular and the plural, unless otherwise indicated herein or
clearly contradicted by context. The terms "comprising," "having,"
"including," and "containing" are to be construed as open-ended
terms (i.e., meaning "including, but not limited to,") unless
otherwise noted. Recitation of ranges of values herein are merely
intended to serve as a shorthand method of referring individually
to each separate value falling within the range, unless otherwise
indicated herein, and each separate value is incorporated into the
specification as if it were individually recited herein. All
methods described herein can be performed in any suitable order
unless otherwise indicated herein or otherwise clearly contradicted
by context. The use of any and all examples, or exemplary language
(e.g., "such as") provided herein, is intended merely to better
illuminate the invention and does not pose a limitation on the
scope of the invention unless otherwise claimed. No language in the
specification should be construed as indicating any non-claimed
element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein,
including the best mode known to the inventors for carrying out the
invention. Variations of those preferred embodiments may become
apparent to those of ordinary skill in the art upon reading the
foregoing description. The inventors expect skilled artisans to
employ such variations as appropriate, and the inventors intend for
the invention to be practiced otherwise than as specifically
described herein. Accordingly, this invention includes all
modifications and equivalents of the subject matter recited in the
claims appended hereto as permitted by applicable law. Moreover,
any combination of the above-described elements in all possible
variations thereof is encompassed by the invention unless otherwise
indicated herein or otherwise clearly contradicted by context.
* * * * *
References